Espionage and Cybercrime campaign Tied to 7-Zip Mark-of-the-Web bypass Hits Ukrainian Institutions
A recently uncovered zero-day vulnerability in the widely used 7-Zip archiver tool has been exploited by Russian hackers to target multiple ukrainian institutions.The flaw, identified as CVE-2025-0411, allowed attackers to bypass Mark-of-the-Web (MotW) protections, enabling the execution of arbitrary code in the context of the current user.This vulnerability was actively exploited in spear-phishing campaigns to deliver the SmokeLoader malware,a notorious payload often used in cyber espionage and crime.
The vulnerability was first discovered by researchers at Trend Micro in September 2024. It was reported to Igor Pavlov, the creator and maintainer of 7-Zip, on October 1, 2024. Pavlov promptly addressed the issue with the release of version 24.09 on November 30, 2024.Despite the patch, the exploit had already been weaponized by Russian cybercrime groups in attacks targeting Ukrainian organizations, including the State Executive Service of Ukraine (SES) under the Ministry of Justice.
The Zero Day Initiative (ZDI), wich relayed the vulnerability details to Pavlov, highlighted the sophistication of the attacks. The hackers employed homoglyph attacks, a technique that uses visually similar characters to deceive users into opening malicious files. This method,combined with the 7-Zip flaw,allowed the attackers to bypass Windows’ MotW protections,which are designed to flag files downloaded from the internet as potentially unsafe.
The SmokeLoader malware delivered through these campaigns is known for its modular architecture, enabling attackers to deploy additional payloads or conduct further reconnaissance. This makes it a potent tool for both cybercrime and nation-state espionage.
Key Details of the 7-Zip Exploit
Table of Contents
- Russian Hackers exploit 7-Zip Vulnerability to target Ukrainian Institutions
| Aspect | Details |
|————————–|—————————————————————————–|
| Vulnerability | CVE-2025-0411 (CVSS score: 7.0) |
| Exploited By | Russian cybercrime groups |
| Target | Ukrainian institutions,including the State Executive Service of Ukraine |
| Malware Delivered | SmokeLoader |
| Patch Release | 7-Zip version 24.09 (November 30, 2024) |
| Discovery | Trend Micro (September 2024) |
The exploitation of this vulnerability underscores the growing intersection of cyberwarfare and cybercrime, where state-sponsored actors leverage tools and techniques traditionally associated with criminal enterprises. The incident also highlights the importance of timely patching and the challenges organizations face in defending against increasingly elegant attacks.
For more insights into the evolving landscape of nation-state attacks and cybercrime, explore our in-depth analysis of North Korea’s secret IT army and strategies to combat such threats.
As the digital battlefield continues to expand, staying informed and vigilant is crucial. Ensure your systems are updated to the latest versions of software like 7-Zip to mitigate risks posed by such vulnerabilities.
Image: Shutterstock
Russian Hackers exploit 7-Zip Vulnerability to target Ukrainian Institutions
In a concerning escalation of cyber warfare,Russian threat actors have been exploiting a critical vulnerability in the popular file compression software 7-Zip to target Ukrainian government agencies and businesses. The vulnerability, tracked as CVE-2025-0411, allows attackers to bypass the Mark-of-the-Web (MOTW) protection mechanism in Windows, enabling the execution of malicious files.
The Vulnerability and Its Exploitation
Discovered by Peter Girnus, a senior threat researcher at Trend Micro, the flaw was first reported to 7-Zip’s creator, Igor Pavlov, on October 1, 2024.Pavlov addressed the issue in the software’s version 24.09 release on November 30, 2024. Though, by then, Russian hackers had already weaponized the vulnerability in active campaigns.
According to a Zero Day Initiative (ZDI) advisory, the exploit requires user interaction, such as visiting a malicious webpage or opening a compromised file. Once triggered, it bypasses MOTW, a Windows feature designed to flag files from untrusted sources and deploy additional security checks like Microsoft Defender SmartScreen.
“Mark-of-the-web poses a barrier to prosperous phishing attacks because the potential victim is offered the opportunity to deny execution,” said Red Canary, a leading cybersecurity firm.The feature also “supplies smartscreen with a hook into the registered AV engine, giving it the opportunity to perform additional signature and reputation checks.”
SmokeLoader Malware Campaign
The exploitation of CVE-2025-0411 is part of a broader campaign involving SmokeLoader, a notorious malware often used by Russian hackers. On September 25, 2024, Trend Micro researchers observed active attacks targeting Ukrainian systems, leveraging compromised accounts tied to government agencies and businesses.
among the targets was the Zaporizhzhia Automobile Building Plant, a major manufacturer of cars, trucks, and buses located in the fiercely contested Zaporizhzhia Oblast region. Other victims included Ukraine’s ministry of Justice, Kyiv’s public transportation service, a water supply company, and several local government bodies such as the Verkhovyna District state Governance and the Zalishchyky City Council.
Private sector entities were not spared either. an appliance and electronics manufacturer, a regional pharmacy, and an insurance firm were also compromised.
Russian Threat Actors and Homoglyph Attacks
Russian government hackers have a long history of using SmokeLoader. In December 2024, Ukraine’s State Service of Special Communications and Information Protection reported that multiple Russian threat groups, including one linked to Russia’s Federal Security Service (FSB), had intensified their use of the malware in campaigns targeting Ukrainian financial institutions.
The latest campaign also employed homoglyph attacks, a technique that uses nearly identical characters to deceive users into opening malicious files or visiting fake websites. This tactic further complicates detection and increases the likelihood of successful phishing attempts.
Key Takeaways
| Aspect | details |
|————————–|—————————————————————————–|
| Vulnerability | CVE-2025-0411 in 7-Zip, bypassing Mark-of-the-Web protection |
| Exploitation | Requires user interaction; used in SmokeLoader malware campaigns |
| Primary Targets | Ukrainian government agencies, critical infrastructure, and private sector |
| Tactics | Homoglyph attacks, compromised legitimate accounts |
| Patch | Fixed in 7-Zip version 24.09, released November 30, 2024 |
Call to Action
Organizations, notably those in high-risk sectors, must ensure they are running the latest version of 7-zip and implement robust cybersecurity measures to mitigate such threats. Regularly updating software, educating employees about phishing tactics, and deploying advanced threat detection solutions are critical steps in defending against sophisticated attacks.
As the cyber conflict between Russia and Ukraine continues to escalate, vigilance and proactive defence strategies are more vital than ever. Stay informed and protect your systems from emerging threats.
Cybercriminals Refine Business Email Compromise Schemes with Homoglyph Attacks
Cybercriminals are increasingly leveraging sophisticated tactics to deceive users, with homoglyph attacks emerging as a prominent tool in their arsenal. These attacks exploit visual similarities between characters to trick victims into clicking malicious links or downloading harmful files. As a notable example,attackers might replace the letter “O” with a zero,transforming a legitimate URL like MICROSOFT.com into MICROS0FT.com. This subtle change can easily go unnoticed, leading unsuspecting users to fall prey to phishing schemes.
A recent example of this strategy was uncovered in the SmokeLoader campaign, where attackers used Cyrillic characters to disguise malicious files. “In the samples we uncovered as part of the SmokeLoader campaign, the inner ZIP archive deployed a homoglyph attack to spoof a Microsoft Windows document ( .doc) file,” explained Trend Micro’s Girnus. By replacing the Latin “S” with the Cyrillic “Es,” the attackers made the archive appear as a harmless Word document.
This deception is particularly effective because it bypasses Mark of the Web (MOTW) protections, which are designed to flag files downloaded from the internet. “This strategy effectively misleads users into inadvertently triggering the exploit for CVE-2025-0411, resulting in the contents of the archive being released without MOTW protections,” Girnus added. Once the file is opened, the attack chain executes JavaScript files designed to steal users’ credentials.
Vulnerabilities in 7-Zip Amplify Risks
The exploitation of homoglyph attacks is further compounded by vulnerabilities in widely used software like 7-Zip. Last November, researchers identified a critical flaw in the software, assigned CVE-2024-11477, which allowed attackers to run arbitrary code on vulnerable installations. Although no active exploits were reported at the time, the discovery highlighted the potential risks.
“Interaction with this library is required to exploit this vulnerability, but attack vectors may vary depending on the implementation,” noted the Zero Day Initiative, which coordinated the fix. This underscores the importance of keeping software updated to mitigate such threats.
Key takeaways
| Aspect | Details |
|————————–|—————————————————————————–|
| Attack Method | Homoglyph attacks using Cyrillic characters to spoof file types. |
| Exploited Vulnerability | CVE-2025-0411 and CVE-2024-11477. |
| Impact | Bypasses MOTW protections, executes JavaScript to steal credentials. |
| Mitigation | Regular software updates and user awareness training. |
Staying Vigilant in a Threatening Landscape
As cybercriminals continue to refine their tactics, users and organizations must remain vigilant. Simple measures like scrutinizing URLs, enabling MOTW protections, and keeping software updated can substantially reduce the risk of falling victim to these schemes. For more insights on emerging cyber threats, explore resources from trend Micro and the Zero Day Initiative.
By understanding the mechanics of these attacks and taking proactive steps, we can better protect ourselves in an increasingly complex digital landscape.
Editor’s interview with Cybersecurity Expert on Homoglyph Attacks and 7-Zip Vulnerabilities
Editor: Welcome! Can you start by explaining what homoglyph attacks are and why they’re so effective?
Expert: Absolutely. Homoglyph attacks exploit the visual similarity between characters from different scripts, such as Latin and Cyrillic. for example, the letter “O” can be replaced with a zero, or the Latin “S” with the Cyrillic “Es.” This subtle manipulation makes it difficult for users to distinguish between legitimate and malicious URLs or file names. It’s particularly effective because it bypasses conventional security measures like Mark of the Web (MOTW) protections, which rely on identifying suspicious file origins.
Editor: How are these attacks being used in campaigns like SmokeLoader?
Expert: in the SmokeLoader campaign,attackers used homoglyphs to disguise malicious files as harmless Microsoft Word documents. by replacing characters in the file names, they tricked users into opening compressed archives that bypassed MOTW protections. Once opened, the files executed JavaScript designed to steal credentials.This tactic is highly deceptive because it leverages the trust users place in familiar file types.
Editor: How do vulnerabilities in 7-Zip, such as CVE-2025-0411, amplify these risks?
Expert: The 7-Zip vulnerability allows attackers to exploit the software’s handling of compressed files. When combined with homoglyph attacks, this flaw can be used to execute arbitrary code on vulnerable systems. As an example, malicious archives can be crafted to appear harmless, but once extracted, they release harmful payloads without triggering MOTW protections. This makes it crucial for users to keep their software updated to patch such vulnerabilities.
Editor: What steps can organizations take to defend against these threats?
Expert: Organizations shoudl prioritize regular software updates, especially for widely used tools like 7-Zip. Employee training is also critical—users need to recognise the signs of phishing attempts, including suspicious URLs and file names. Additionally, deploying advanced threat detection solutions can help identify and block malicious activities before they cause harm.
Editor: How does the ongoing cyber conflict between Russia and Ukraine factor into these threats?
Expert: the heightened tensions have led to an increase in complex cyberattacks targeting Ukrainian government agencies and critical infrastructure. Attackers are leveraging vulnerabilities like CVE-2025-0411 to deliver malware and steal sensitive data. This underscores the need for heightened vigilance and robust cybersecurity measures in high-risk sectors.
Editor: What’s your advice for users and organizations to stay safe in this evolving landscape?
Expert: Stay informed about emerging threats and implement a layered defense strategy. Regularly update software, educate employees about phishing tactics, and use advanced security tools to detect and mitigate threats. In a landscape were cybercriminals are constantly refining their methods, proactive measures are essential to staying one step ahead.
Conclusion
Homoglyph attacks and software vulnerabilities like those in 7-Zip pose notable risks, particularly in high-stakes environments like the ongoing Russia-Ukraine conflict. By understanding these threats and taking proactive steps, organizations can better protect themselves against increasingly sophisticated cyberattacks. Stay updated, stay vigilant, and invest in robust cybersecurity measures to safeguard your systems and data.
